Perhaps it's a jurisdictional thing, then? Where I live, if it's in public, it's fair game. The only exception is when it's in public but there is a reasonable expectation of privacy. For example, even though a fenced backyard is outside, someone reaching a camera above the fence to record is an invasion of privacy. Recording someone in their unfenced front yard from the street is not an invasion of privacy, unless the recording was meant to record what's inside the house through the windows.